Inflammatory Bowel Diseases (IBD) is a broad term that describes conditions with chronic or recurring immune response and inflammation of the gastrointestinal tract. Crohn's disease (CD) and ulcerative colitis (UC), the two common forms of idiopathic inflammatory bowel disease (IBD), are chronic, relapsing inflammatory disorders of the gastrointestinal tract. The peak age of onset for IBD is 15 to 30 years old, although it may occur at any age. About 10% of cases occur in individuals younger than 18 years. Ulcerative colitis is slightly more common in males, whereas Crohn's disease is marginally more frequent in women. IBD is one of the five most prevalent gastrointestinal disease burdens in the United States, with an overall health care cost of more than $1.7 billion. It is estimated that as many as 1.4 million persons in the United States suffer from these diseases.
The precise etiology of IBD remains to be elucidated. Genetic factors play an important role in IBD pathogenesis, as evidenced by the increased rates of IBD in Ashkenazi Jews, familial aggregation of IBD, and increased concordance for IBD in monozygotic compared to dizygotic twin pairs (Vermeire et al., Genes Immun 6, 637 (2005)). CD and UC are thought to be related disorders that share some genetic susceptibility loci but differ at others.
Thus, there remains a need in the art to develop methods to treat or prevent IBD, as well as to determine other genes or allelic variants that may assist in explaining the genetic risk, diagnosing, and/or predicting susceptibility or risk for inflammatory bowel disease including but not limited to CD and/or UC.